Ambient cure water-based coatings for writable-erasable surfaces

ABSTRACT

Water-based coatings having writable-erasable surfaces are provided. The coatings have many desirable attributes. For example, the coatings cure under ambient conditions, have low or no VOC emissions during and upon curing, and have reduced tendency to form ghost images, even after prolonged normal use.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of PCT Patent ApplicationSerial No. PCT/US2007/073524, filed on Jul. 13, 2007, the completedisclosure of which is incorporated by reference herein.

TECHNICAL FIELD

This disclosure relates to water-based coatings for writable-erasablesurfaces, products that include such coatings, and to the methods ofmaking the same.

BACKGROUND

Classroom education has traditionally relied upon a “blackboard” andchalk as an instruction medium. This technique can be messy, dusty, andmany blackboards cannot be used with all chalk types and colors. Thedust generated can lead to many respiratory afflictions. Overheadprojectors, laptop computers and dry erase boards (often referred tocommonly as “whiteboards”) are alternatives to traditional blackboards.

Dry erase boards typically include a substrate, such as paper or board,and a coating, such as a lacquer coating, extending upon the substrate.The coating provides a writing surface that can be marked using dryerase marking pens. Dry erase marking pens, which are typically felt tipmarking instruments, contain inks that not only can mark such surfaces,but also can be erased with minimal effort using, e.g., a dry eraser,cloth, or paper tissue.

The erasability of dry erase inks from the writing surfaces of dry eraseboards can deteriorate over time, resulting in the formation ofnon-removable “ghost images.” In addition, such surfaces can beincompatible with some dry erase markers, and can be permanently markedif inadvertently written on with a permanent marker.

SUMMARY

This disclosure relates to coatings having writable-erasable surfaces,products that include such coatings (e.g., whiteboards), and to methodsof making and using the same. Generally, the coatings having thewritable-erasable surfaces are produced from one or more precursormaterials in a water-based carrier; the coatings cure under ambientconditions. When the writing surface is marked with a marking material,such as a water- or alcohol-based marking material, the marking materialcan be erased to be substantially invisible with little or no ghosting,even after prolonged and repeated use. The one or more materials thatform the coatings emit minimal volatile organic compounds (VOCs) duringtheir application to a substrate or during their curing on thesubstrate. The resulting coatings have many desirable attributes,including one or more of the following: low porosity, low surfaceroughness, high elongation at break, high Taber abrasion resistance, andhigh Sward hardness. Generally, while not intending to be bound by anytheory, it is believed that the low porosity of the coatings makes thecoatings substantially impervious to the marking materials, while thelow surface roughness prevents the marking materials from becomingentrapped on the surface beyond effective reach of an eraser.

In one aspect of the disclosure, a writable-erasable product includes acured coating (such as crosslinked) extending upon a substrate andhaving a writable-erasable surface. The coating is curable under ambientconditions, and can be formed from one or more materials, each of theone or more materials including one or more functional groupsindependently selected from G1 and G2, with at least one material of theone or more materials in a water-based carrier, wherein each G1functional group is independently selected from among isocyanate,epoxide, urethane, ethyleneoxy, and ethylene, wherein the ethylene isoptionally substituted with hydroxyl, acetoxy, or alkoxycarbonyl; andeach G2 functional group is independently selected from among hydroxyl,amine, phenol, carboxylic acid, acid anhydride, aziridine, and thiol.After the writable-erasable surface is marked with a marking materialincluding a colorant and a solvent, the solvent including one or more ofwater, alcohols, alkoxy alcohols, ketones, ketonic alcohols, esters,acetates, mineral spirits, or mixtures thereof, the marking material canbe erased from the writable-erasable surface to be substantiallyinvisible.

In some implementations, the coating can be formed from one or morematerials, each of the one or more materials including one or more G1functional groups, with at least one material of the one or morematerials in a water-based carrier.

In some implementations, the coating can be formed from two or morematerials, wherein a first material includes one or more G1 functionalgroups and a second material includes one or more G2 functional groups,with at least one material of the two or more materials in a water-basedcarrier.

In some implementations, the cured coating and/or the writable-erasablesurface may have one or more of the following attributes. The coatingmay have a porosity of less than about 40 percent; a thickness of fromabout 0.001 inch to about 0.125 inch; a Taber abrasion value of fromabout 100 to about 125 mg/thousand cycles; a Sward hardness of greaterthan about 10; an elongation at break of between about 5 percent toabout 400 percent; a sag resistance of between about 4 and about 24; aVOC content of less than about 350 g/L (such as less than about 50 g/L).

In some implementations, G1 is isocyanate, epoxide, urethane,ethyleneoxy, and/or ethylene optionally substituted with hydroxyl,acetoxy, or alkoxycarbonyl.

In some implementations, G1 is ethylene substituted with alkoxycarbonyl,or ethylene optionally substituted with acetoxy.

In some implementations, the one or more materials including one or moreG1 groups wherein G1 is ethylene substituted with alkoxycarbonyl,further includes one or more materials including one or more G1 groupswherein G1 is ethyleneoxy.

In some implementations, the one or more materials is a polyurethane. Insuch implementations, the one or more materials can further include apolyacrylate.

In some implementations, the one or more materials is in the form of adispersion.

In some implementations, G2 is hydroxyl, amine, phenol, carboxylic acid,acid anhydride, aziridine, and/or thiol.

In some implementations, when G1 is epoxide, G2 can be hydroxyl oramine; when G1 is isocyanate, G2 can be hydroxyl or amine; and/or whenG1 is urethane, G2 can be aziridine.

In some implementations, the one or more materials including one or moreG1 functional group can be selected from hexamethylene diisocyanate(HDI), tetramethylene diisocyanate, octamethylene diisocyanate,decamethylene diisocyanate, 2-methylpentane-1,5-diisocyanate, toluenediisocyanate (TDI), diphenylmethane diisocyanate (MDI), m- andp-phenylene diisocyanates, bitolylene diisocyanate, cyclohexanediisocyanate (CHDI), bis-(isocyanatomethyl)cyclohexane (H6XDI),dicyclohexylmethane diisocyanate (H12MDI), dimer acid diisocyanate(DDI), trimethyl hexamethylene diisocyanate, lysine diisocyanate and itsmethyl ester, methyl cyclohexane diisocyanate, 1,5-napthalenediisocyanate, xylene diisocyanate, polyphenylene diisocyanates,isophorone diisocyanate (IPDI), hydrogenated methylene diphenylisocyanate (HMDI), tetramethyl xylene diisocyanate (TMXDI), or theiroligomers and homopolymers, and their mixtures.

In some implementations, the one or more materials including one or moreG1 functional group includes an aliphatic diisocyanate (e.g.,hexamethylene-1,6-diisocyanate, IPDI and the like) such as anhydrophilic aliphatic diisocyanate or their oligomers and homopolymers(e.g., homopolymer of hexamethylene-1,6-diisocyanate), or theirmixtures.

In some implementations, the one or more materials including one or moreG1 functional group includes a polymeric material.

In some implementations, the one or more materials including one or moreG2 functional group includes an α,ω-diol.

In some implementations, the one or more materials including one or moreG2 functional group includes a polymeric material (e.g., an acrylicpolyol or an acrylic based diol).

The writable-erasable surface can be erased to be substantiallyinvisible after writing and erasing at the same position for more thanabout 100 cycles, or even more than about 5,000 cycles. Thewritable-erasable surface can have an average surface roughness (R_(a))of less than about 7,500 nm; a maximum surface roughness (R_(m)) of lessthan about 10,000 nm; a contact angle of greater than about 35 degrees;a contact angle of less than about 150 degrees.

In some implementations, the substrate can be selected from the groupconsisting of cellulosic material, glass, wall (such as plaster orpainted), fiber board (e.g., a whiteboard in which the cured coating canextend upon a fiber board), particle board (e.g., a chalkboard orblackboard), gypsum board, wood, densified ceramics, stone (such asgranite), and metal (such as aluminum or stainless steel).

In some implementations, the substrate can be selected from a flexiblefilm or a rigid immovable structure.

In some implementations, the marking material can be erased from thewritable-erasable surface to be substantially invisible by wiping themarks with an eraser including a fibrous material.

In some implementations, the eraser includes water, alcohol (e.g.,ethanol, n-propanol, isopropanol, n-butanol, isobutanol, benzylalcohol), alkoxy alcohol (e.g., 2-(n-propoxy) ethanol, 2-(n-butoxy)ethanol, 3-(n-propoxy) ethanol), ketone (e.g., acetone, methyl ethylketone, methyl n-butyl ketone), ketonic alcohol (e.g., diacetonealcohol), ester (e.g., methyl succinate, methyl benzoate, ethylpropanoate), acetate (e.g., methyl acetate, ethyl acetate, n-butylacetate, t-butyl acetate), or mineral spirit.

In some implementations, the writable-erasable product can form awhiteboard in which the cured coating extends upon a fiberboard; canform a part of a wall e.g., of a structure; or can form a plurality ofsheets, each sheet including a substrate (e.g., in the form of a paper)having the cured coating extending thereupon.

In another aspect, the disclosure describes a method of making awritable-erasable product, the method including applying a coating to asubstrate, and curing the coating (e.g., under ambient conditions) toprovide a cured coating defining a writable-erasable surface. After thewritable-erasable surface is marked with a marking material, the markingmaterial can be erased from the writable-erasable surface to besubstantially invisible.

In such implementations, the coating includes one or more materials,each of the one or more materials including one or more functionalgroups independently selected from G1 and G2, with at least one materialof the one or more materials in a water-based carrier, wherein each G1functional group is independently selected from among isocyanate,epoxide, urethane, ethyleneoxy, and ethylene, wherein the ethylene isoptionally substituted with hydroxyl, acetoxy, or alkoxycarbonyl; andeach G2 functional group is independently selected from among hydroxyl,amine, phenol, carboxylic acid, acid anhydride, aziridine, and thiol.

In such implementations, the marking material includes a colorant and asolvent (e.g., water, alcohol, alkoxy alcohol, ketone, ketonic alcohol,ester, acetate, mineral spirit, or their mixtures).

In some implementations, the coating prior to application has less thanabout 350 g/L of VOCs (e.g., less than about 50 g/L of VOCs).

In some implementations, the coating can be prepared by combining theone or more materials including one or more G1 functional group (e.g.,an isocyanate), and the one or more materials including one or more G2functional group (e.g., an hydroxyl).

In some implementations, prior to combining, the one or more materialsincluding one or more G1 functional group (e.g., an isocyanate) can bein a first container, and the one or more materials including one ormore G2 functional group (e.g., an hydroxyl) can be in a secondcontainer.

In some implementations, the one or more materials including one or moreG2 functional group (e.g., an hydroxyl) also includes a crosslinkingagent having a functionality of two or greater.

In some implementations, the one or more materials can be in awater-based carrier.

In another aspect, the disclosure describes a method of changeablypresenting information including selecting a writable-erasable product,marking the writable-erasable surface with a first information with amarking material. After the surface has been marked with the markingmaterial, erasing the marking of the first information (e.g., byapplying an eraser to the writable-erasable surface) from thewritable-erasable surface to be substantially invisible; marking thewritable-erasable surface with a different information and erasing themarking of the different information from the writable-erasable surfaceto be substantially invisible.

In some implementations, the coating can be formed from one or morematerials, each of the one or more materials including one or morefunctional groups independently selected from G1 and G2, at least onematerial of the one or more materials in a water-based carrier, whereineach G1 functional group is independently selected from amongisocyanate, epoxide, urethane, ethyleneoxy, and ethylene, wherein theethylene is optionally substituted with hydroxyl, acetoxy, oralkoxycarbonyl; and each G2 functional group is independently selectedfrom among hydroxyl, amine, phenol, carboxylic acid, acid anhydride,aziridine, and thiol.

In some implementations, the coating can be formed from one or morematerials including one or more isocyanate groups, one or more materialsincluding one or more hydroxyl groups, at least one material of the oneor more materials in a water-based carrier.

In some implementations, the marking material includes a colorant and asolvent (e.g., water, alcohol, alkoxy alcohol, ketone, ketonic alcohol,ester, acetate, mineral spirit, or their mixtures).

In some implementations, the eraser includes a fibrous material.

In some implementations, the eraser includes water, alcohol, alkoxyalcohol, ketone, ketonic alcohol, ester, acetate, mineral spirit, ortheir mixtures.

In some implementations, the marking and erasing of differentinformation are performed repeatedly.

In another aspect, the disclosure describes a composition including anhydrophilic aliphatic diisocyanate or their homopolymers and oligomers,an acrylic polyol, water, and optionally an accelerator and/or an acidpromoter.

In some implementations, the composition can include titanium dioxide, asurface additive, a wetting agent, a defoaming agent, a pigment or acolorant.

In some implementations, the composition can have less than about 350g/L of VOCs (e.g., less than about 50 g/L of VOCs).

In another aspect, the disclosure describes a writable-erasable productincluding a cured coating extending upon a substrate and having awritable-erasable surface. The coating can cure under ambient conditionsand can be formed from a material in a water-based carrier. After thewritable-erasable surface is marked with a marking material, including acolorant and a solvent (e.g., water, alcohol, alkoxy alcohol, ketone,ketonic alcohol, ester, acetate, mineral spirit, or their mixtures), themarking material can be erased from the writable-erasable surface to besubstantially invisible.

Implementations and/or aspects may include one or more of the followingadvantages. The coating surfaces are writable and erasable. The coatingscan provide writing surfaces that exhibit little or no image ghosting,even after prolonged normal use. The coatings can be simple to prepare,and can be applied to many different substrates, including both porous(e.g., paper) and non-porous substrates (e.g., densified ceramics). Thecoatings can be applied to various substrates including, but not limitedto, old chalkboards (e.g., blackboards), whiteboards, drywalls, gypsumboards, plaster and painted walls. The water-based coatings can beapplied on the substrate on-site to make a writable-erasable productrather than the writable-erasable product being manufactured in afactory. For many substrates, a single coating can provide an adequatewritable-erasable surface. The coatings can exhibit good adhesivestrength to many substrates. Coating components (prior to mixing) canhave an extended shelf-life, e.g., up to about three years. The coatingscan be readily resurfaced. The coatings can cure rapidly, e.g., in lessthan 4 hours, under ambient conditions. The coatings can resistyellowing, as determined by ASTM method G-154, for an extended period oftime (e.g., up to 2000 hours). The coatings do not require UV light orhigh-energy radiation, such as a beam of electrons, for curing.Nevertheless, in some implementations, light, e.g., UV light, or heatcan be utilized to enhance the curing rate. The coatings can have areduced tendency to run, even when applied upon a vertical substrate.Surface gloss of the coatings can be readily adjusted. The writingsurface of the coating can be projectable. The coatings can be hard. Thecoatings can be substantially impervious to organic solvents and/orinks. The coatings can have a low porosity. Surfaces of the coatings canhave a low roughness. The coatings can be impact resistant. The coatingscan be made scratch and abrasion resistant. The coatings can berelatively low cost. The coatings can have a high chemical resistance.

“Curing” as used herein refers to one or more of solvent evaporation(drying), radiation effected curing, coalescence, catalyzedpolymerization, oxidative cross-linking, or other methods ofcross-linking.

“Ambient conditions” as used herein refers to nominal, earth-boundconditions as they exist at sea level at a temperature of about 45-130°F.

A “water-based carrier” as used herein is one that does not have morethan about 350 g/L of volatile organic compounds (VOCs), as determinedby the EPA Method 24.

“Substantially invisible” as used herein refers to a color difference,Delta E (ΔE) of less than 10 as calculated according to the ASTM TestMethod D2244.

“Alkyl” as used herein refers to a saturated or unsaturated hydrocarboncontaining 1-20 carbon atoms including both acyclic and cyclicstructures (such as methyl, ethyl, propyl, isopropyl, butyl, iso-butyl,sec-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, propenyl, butenyl, cyclohexenyl and the like). A linkingdivalent alkyl group is referred to as an “alkylene” (such as ethylene,propylene and the like).

As used herein, “aryl” refers to monocyclic or polycyclic (e.g., having2, 3 or 4 fused rings) aromatic hydrocarbons such as phenyl, naphthyl,anthracenyl, phenanthrenyl, indanyl, indenyl, and the like. In someembodiments, aryl groups have from 6 to about 20 carbon atoms, from 6 toabout 15 carbon atoms, or from 6 to about 10 carbon atoms.

As used herein, “aralkyl” refers to alkyl substituted by aryl. Anexample aralkyl group is benzyl.

As used herein, “alkoxy” refers to an —O-alkyl group. Example alkoxygroups include methoxy, ethoxy, propoxy (e.g., n-propoxy andisopropoxy), t-butoxy, and the like.

As used herein, “oxyalkylene” refers to an —O-alkylene group.

As used herein, “alkoxylate” refers to an alkyl-C(O)O. Examplealkoxylates include acetate, stearate and the like.

A “polyol” as used herein is a moiety that includes at least twohydroxyl (—OH) groups. The hydroxyl groups can be terminal and/ornon-terminal. The hydroxyl groups can be primary hydroxyl groups.

A “polyurethane” as used herein is a polymeric or oligomeric materialthat includes a urethane linkage, [NHC(═O)O], in its backbone.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference herein in their entirety.

The details of one or more implementations of the disclosure are setforth in the accompanying drawings, and in the description below. Otherfeatures, and advantages will be apparent from the description anddrawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a top view of a writable-erasable product.

FIG. 1A is a cross-sectional view of the writable-erasable product ofFIG. 1, taken along 1A-1A.

FIG. 2 is a cross-sectional view of a droplet of water on a coating andillustrates a method for determining contact angle.

FIG. 3 is a perspective view of a coated roll of paper.

FIG. 4 is a perspective view of a tablet of coated papers formed fromthe roll of FIG. 3.

Like reference symbols in various drawings indicate like elements.

DETAILED DESCRIPTION Writable-Erasable Product

Referring to FIGS. 1 and 1A, a writable-erasable product 10 includes asubstrate 12 and a cured coating 14 extending upon the substrate 12. Thecoating 14 has a writable-erasable surface 16. When thewritable-erasable surface 16 is marked with a marking material, themarking material can be erased from the writable-erasable surface to besubstantially invisible, resulting in little or no ghosting, even afterprolonged normal use, e.g., after about 5,000 cycles (e.g., about 10cycles, about 50 cycles, about 100 cycles, about 500 cycles, about 1,000cycles, about 2,000 cycles, about 3,000 cycles, about 4,000 cycles,about 5,000 cycles, about 6,000 cycles, about 7,000 cycles, about 8,000cycles, or about 9,000 cycles) of writing and erasing at the sameposition. The visibility, or the lack thereof, of the erasing can bedetermined by measuring the color change, Delta E (ΔE), on thewritable-erasable surface using a spectrophotometer (such as the SP-62portable spectrophotometer available from X-Rite), after marking on thesurface and erasing the marking. The marking material can include acolorant (e.g., a pigment) and a solvent such as water, alcohol,acetate, alkoxy alcohol, ketone, ketonic alcohol, ester, acetate,mineral spirit, or mixtures thereof. The marking material can beselected from any of the industry standard dry-erase markers.

The materials that form the coating 14 can be applied to many differenttypes of substrates, including porous (e.g., paper) and non-poroussubstrates (e.g., densified ceramics). The substrate 12 could be aflexible film or a rigid movable or immovable structure. Examples of thesubstrate include, but are not limited to, a polymeric material (such aspolyester or polyamide), cellulosic material (such as paper), glass,wood, wall (such as plaster or painted), fiber board (such as awhiteboard in which the cured coating extends upon a fiber board),particle board (such as a chalkboard or blackboard), gypsum board,densified ceramics, stone (such as granite), and metal (such as aluminumor stainless steel). The substrate could be a newly built structure oreven a old and worn out chalkboard, blackboard, or whiteboard. In someinstances, the surface of the substrate can be cleaned by sanding thesurface and priming the surface prior to application of the coating. Insome instances, the surface can also be cleaned with a cleaning agent(e.g., a mild acid) in order to provide better adhesion of the coatingto the surface.

The materials that form the coating 14, prior to the application onsubstrates, can have a pot life which is the time during which thematerials must be applied on the substrate. In some implementations, thematerials can have a pot life of from about 10 minutes to about 16hours, e.g., from about 30 minutes to about 12 hours, from about 60minutes to about 8 hours, from about 1 hour to about 4 hours, or fromabout 1 hour to about 2 hours. In other implementations, the materialscan have a pot life of greater than about 6 months, e.g., about 12months, about 18 months, about 24 months, about 30 months, or about 36months.

The materials that form the coating 14, upon application to thesubstrates, typically cure under ambient conditions. Curing, here,refers to the process of setting of the materials that form the coatingon the substrate. It could refer to the process of simple evaporation ofthe solvent from the materials that form the coating; the differentmethods of cross-linking among the materials that form the coatingincluding, but not limited to, oxidative cross-linking and catalyzedpolymerization. Cross-linking between polymeric chains, either chemicalor physical, can influence certain unique properties of coatings. Insome optional implementations, the cure could be facilitated byUV-light, thermal means, initiators, or electron-beam. The coating 14can cure under ambient conditions in from about 4 hours to about a week,e.g., from about 4 hours to about 24 hours, from about 8 hours to about20 hours, from about 12 hours to about 16 hours, from about 1 day toabout 7 days, from about 2 days to about 6 days, or from about 3 days toabout 5 days.

The materials that form the coating 14, emit little or no VOCs, e.g.,solvents and/or formaldehyde, during application to the substrate 12.The cured coatings 14 can be generally stable and can also emitrelatively little or no VOCs. The decreased amount of volatile content(usually solvents) and ambient cure can reduce environmental impact andcan make the materials less toxic (decreased inhalation and absorption)and safer (decreased flammability and flash point) to use. The reducedemission of organic solvents during the application of the water-basedcoating ensures that the application area need not be isolated fromother areas, need not be well ventilated, and that little or no personalprotection equipment is required. The use of ambient cure materialallows for energy efficiency during the curing process as compared tocuring processes that require energy in the form of radiation. Thereduced amounts of organic solvents can also lead to increased pot lifeof the coating material and hence decreased material waste. Low VOCemissions and ambient cure can also provide coatings and/orwritable-erasable surfaces that have one or more of the desirableattributes, such as low porosity, low surface roughness, high elongationat break, high Taber abrasion resistance, and high Sward hardness.

In some implementations, the material has less than about 350 g/L ofVOCs, e.g., about 300 g/L, about 250 g/L, about 200 g/L, about 150 g/L,about 100 g/L, about 50 g/L, or even less than about 0.5 g/L of VOCs. Inother implementations, the material has between about 0 and about 50 g/Lof VOCs, e.g., between about 1 g/L and about 10 g/L, between about 10g/L and about 20 g/L, between about 20 g/L and about 30 g/L, betweenabout 30 g/L and about 40 g/L, or between about 40 g/L and about 50 g/Lof VOCs. The material may also be substantially free of VOCs.Advantageously, when a VOC is utilized, it can be a VOC that is exemptedfrom United States Environmental Protection Agency (EPA) guidelines,e.g., methyl acetate, t-butyl acetate, isopropyl alcohol, or acetone.

Porosity of the coatings can determine the amount of marking materialthat can be trapped in the coating. Lower porosity percentages ofcoatings can lead to better writable-erasable surfaces. In someimplementations, the coating 14 can have a porosity of between about 1percent and about 40 percent, e.g., between about 2 percent and about 35percent, between about 2.5 percent and about 30 percent, between about 3percent and about 20 percent, or between about 4 percent and about 10percent. In other implementations, the coating 14 can have a porosity ofless than about 40 percent, e.g., less than about 35 percent, less thanabout 30 percent, less than about 25 percent, less than about 20percent, less than about 15 percent, less than about 10 percent, lessthan about 5 percent, or even less than about 2.5 percent. In somespecific implementations, the coating can have a porosity of about 3percent, about 33 percent or about 34 percent.

The coating 14 can be painted in a single coat or multiple coats using aroller, spray painted, brush painted or using other types ofapplicators. In some implementations, it can be painted using a foamroller in a single coat. In some implementations, the coating 14 canhave a thickness, T (FIG. 1A), e.g., between about 0.001 inch and about0.125 inch, e.g., between about 0.002 inch and about 0.1 inch, orbetween about 0.004 inch and about 0.08 inch, or between about 0.006inch and about 0.06 inch, or between about 0.008 inch and about 0.04inch, or between about 0.01 inch and about 0.02 inch. In otherimplementations, the coating 14 can have a thickness of greater than0.005 inch, e.g., greater than 0.0075 inch or greater than 0.010 inch.While not intending to be bound by any theory, it is believed thatproviding an uniform, adequate coating thickness, T, reduces thelikelihood of thin or uncoated substrate portions where marking materialmight penetrate.

In some implementations, the coating 14 can have a Taber abrasion valueof less than about 150 mg/thousand cycles, e.g., less than about 100mg/thousand cycles, less than about 75 mg/thousand cycles, less thanabout 50 mg/thousand cycles, less than about 35 mg/thousand cycles, lessthan about 25 mg/thousand cycles, less than about 15 mg/thousand cycles,less than about 10 mg/thousand cycles, less than about, less than about2.5 mg/thousand cycles, less than about 1 mg/thousand cycles, or evenless than about 0.5 mg/thousand cycles. Maintaining a low Taber abrasionvalue can provide long-lasting durability to the coating, reducing theincidence of thin spots, which could allow penetration of markingmaterial through the coating and into the substrate.

In some implementations, the coating 14 can have a Sward hardness ofgreater than about 10, e.g., greater than about 15, greater than about25, greater than about 50, greater than about 75, greater than about100, greater than about 120, greater than about 150, or even greaterthan about 200. While not intending to be bound by theory, it isbelieved that maintaining a high Sward hardness provides long-lastingdurability and scratch resistance to the coating. Marking materialentrapped in scratches can be difficult to erase.

In some specific implementations, the coating can have a Sward hardnessof between about 10 and about 75, e.g., between about 15 and about 70 orbetween about 15 and about 55. In some specific implementations, thecoating can have a Sward hardness of about 15, about 22 or about 25.

In some implementations, elongation at break for the coating materialcan be between about 5 percent and about 400 percent, e.g., betweenabout 25 percent and about 200 percent, or between about 50 percent andabout 150 percent. In other implementations, the elongation at break canbe, e.g., greater than 10 percent, e.g., greater than 25 percent,greater than 50 percent, or even greater than 100 percent. While notintending to be bound by theory, it is believed that maintaining highelongation at break provides long-lasting durability to the coating, andit allows the coating to be stressed without cracks forming. Cracks cantrap marking materials, making erasure from surfaces difficult and hencedecreasing the longevity of the writable-erasable products.

In some implementations, sag resistance for the coating material can beabout 8 mils, e.g., about 3 mils, about 4 mils, about 5 mils, about 6mils, about 7 mils, about 8 mils, about 9 mils, about 10 mils, about 12mils, about 14 mils, about 16 mils, about 18 mils, about 20 mils, about22 mils, or about 24 mils. In other implementations, the coating 14 canhave sag resistance of from about 4 mils to about 24 mils, e.g., fromabout 5 mils to about 20 mils, from about 6 mils to about 18 mils, fromabout 7 mils to about 16 mils, from about 8 mils to about 14 mils, fromabout 9 mils to about 12 mils, or from about 10 mils to about 12 mils.

In some implementations, the writable-erasable surface can have anaverage surface roughness (R_(a)) of, e.g., between about 0.5 nm andabout 7,500 nm, e.g., between about 1 nm and about 6,000 nm, betweenabout 2 nm and about 5,000 nm, between about 5 nm and about 2,500 nm,between about 10 nm and about 1,500 nm, between about 20 nm and about1,000 nm or between about 25 nm and about 750 nm. In otherimplementations, the coating 14 can have an average surface roughness(R_(a)) of less than about 7,500 nm, e.g., less than about 5,000 nm,less than about 3,000 nm, less than about 2,000 nm, less than about1,000 nm, less than about 500 nm, less than about 250 nm, less thanabout 200 nm, less than about 100 nm, or even less than about 50 nm.

In some specific implementations, the writable-erasable surface can havean average surface roughness (R_(a)) of between about 75 nm and about1,000 nm, e.g., between about 100 nm and about 500 nm or between about150 nm and about 400 nm. In some specific implementations, thewritable-erasable surface can have an average surface roughness (R_(a))of about 150 nm, about 300 nm or about 1,000 nm.

In some implementations, the writable-erasable surface can have amaximum surface roughness (R_(m)) of less than about 10,000 nm, e.g.,less than about 8,000 nm, less than about 6,500 nm, less than about5,000 nm, less than about 3,500 nm, less than about 2,000 nm, less thanabout 1,000 nm, or less even than about 500 nm.

In some implementations, the writable-erasable surface can have a flatfinish (gloss below 15, measured at 85 degrees), an eggshell finish(gloss between about 5 and about 20, measured at 60 degrees), a satinfinish (gloss between about 15 and about 35, measured at 60 degrees), asemi-gloss finish (gloss between about 30 and about 65, measured at 60degrees), or gloss finish (gloss greater than about 65, measured at 60degrees).

In some specific implementations, the writable-erasable surface can havea 60 degree gloss of between about 45 and about 90, e.g., between about50 and about 85. In other implementations, the writable-erasable surfacecan have a 20 degree gloss of between about 10 and about 50, e.g.,between about 20 and about 45. In still other implementations, thewritable-erasable surface can have a 85 degree gloss of between about 45and about 90, e.g., between about 75 and about 90. In other specificimplementations, the writable-erasable surface can have a 20 degreegloss of about 12, about 23, or about 46; or a 60 degree gloss of about52, about 66, or about 85; or a 85 degree gloss of about 64, about 78,or about 88.

In some implementations, to improve the writability and erasability ofthe surface of the coating, precursor materials can be chosen so thatthe cured coating has a surface that is relatively hydrophilic and notvery hydrophobic. Referring to FIG. 2, hydrophobicity of thewritable-erasable surface is related to its wetability by a liquid,e.g., water-based marking material. It is often desirable to quantitatethe hydrophobicity of the writable-erasable surface by a contact angle.Generally, as described in ASTM D 5946-04, to measure contact angle, θ,for a liquid (such as water) on the writable-erasable surface 16, anangle is measured between the writable-erasable surface 16 and a tangentline 26 drawn to a droplet surface of the liquid at a three-phase point.Mathematically, θ is 2 arctan(A/r), where A is the height of the dropletimage, and r is half width at the base. In some implementations, it canbe desirable to have contact angle, θ, measured using deionized water,of less than about 150 degrees, e.g., less than about 125 degrees, lessthan about 100 degrees, less than about 75 degrees or even less thanabout 50 degrees. In other implementations, it can be desirable to havecontact angle θ above about 35 degrees, e.g., above about 40 degrees,above about 45 degrees.

In certain implementations, contact angle, θ, measured using deionizedwater, can be between about 30 degrees and about 90 degrees, e.g.,between about 45 degrees and about 80 degrees, or between about 39degrees and about 77 degrees. In some specific implementations, thecontact angle can be about 40 degrees, about 50 degrees, about 60degrees, about 73 degrees, or about 77 degrees.

In some implementations, the writable-erasable surface can have asurface tension of between about 30 dynes/cm and about 60 dynes/cm,e.g., between about 40 dynes/cm and about 60 dynes/cm. In some specificimplementations, the writable-erasable surface can have a surfacetension of about 25 dynes/cm, about 30 dynes/cm, about 42 dynes/cm,about 44 dynes/cm or about 56 dynes/cm.

In general, the coating 14 can be formed by applying, e.g., rolling,painting, or spraying, a solution of the material in a water-basedcarrier that can have a sufficient viscosity such that the appliedcoating does not run soon after it is applied or during its curing. Atthe same time, the solution viscosity should be sufficient to permiteasy application. For example, in some implementations, the appliedsolution can have a viscosity at 25° C. of between about 75 mPa·s andabout 20,000 mPa·s, e.g., between about 200 mPa·s and about 15,000mPa·s, between about 1,000 mPa·s and about 10,000 mPa·s, or betweenabout 750 mPa·s and about 5,000 mPa·s.

Advantageously, when the writable-erasable surface is marked with amarking material that includes a colorant and a solvent that includesone or more of water, alcohols, alkoxy alcohols, ketones, ketonicalcohols, esters, acetates or mineral spirits, the marking material canbe erased from the writable-erasable surface to be substantiallyinvisible. Mixtures of any of the noted solvents may be used. Forexample, mixtures of two, three, four or more of the noted, or other,solvents may be used.

In some implementations, the marking material can be erased from thewritable-erasable surface to be substantially invisible by wiping themarks with an eraser that includes a fibrous material. For example, theeraser can be in the form of a disposable wipe or a supported (e.g.,wood, plastic) felt. The eraser can also include, e.g., one or more ofwater, alcohols, alkoxy alcohols, ketones, ketonic alcohols, esters,acetates or mineral spirits. Mixtures of any two or more of thesesolvents may also be used.

Examples of alcohols include ethanol, n-propanol, iso-propanol,n-butanol, iso-butanol, and benzyl alcohol. Mixtures of any two or moreof these solvents also represent alcohols.

Examples of alkoxy alcohols include 2-(n-propoxy) ethanol, 2-(n-butoxy)ethanol and 3-(n-propoxy) ethanol. Mixtures of any two or more of thesesolvents also represent alkoxy alcohols.

Examples of ketones include acetone, methyl ethyl ketone and methyln-butyl ketone. Mixtures of any two or more of these solvents may alsobe utilized.

Examples of acetates include methyl acetate, ethyl acetate, n-butylacetate and t-butyl acetate. Mixtures of any two or more of thesesolvents may also be utilized.

For testing, the coating can be made by casting the material on afluoropolymer substrate, and then curing the material so that it canhave a dry thickness of about 0.002 inch. The cured sample can then beremoved from the fluoropolymer substrate to provide the test specimen.Testing can be performed at 25° C. Elongation at break can be performedusing ASTM method D-882; porosity can be measured using mercuryporosimetry (suitable instruments available from Micromeritics,Norcross, Ga., e.g., Micromeritics Autopore IV 9500); surface roughnesscan be measured using atomic force microscopy (AFM) in tapping modeusing ASME B46.1 (suitable instruments, e.g., WYKO NT8000, are availablefrom Park Scientific); Taber abrasion resistance can be measuredaccording to ASTM method D-4060 (wheel CS-17, 1 kg load) and Swardhardness can be measured according to ASTM method D-2134 (Sward HardnessRocker Model C). The amount of VOCs can be determined using the EPAMethod 24. Gloss can be measured using ASTM method D-523-89 (BYKTri-Gloss Meter Cat. No. 4525). Contact angle can be measured withdeionized water using the dynamic contact angle method (Angstroms ModelFTA 200) using ASTM method D-5946-04. Sag resistance can be measuredusing ASTM method D4400. This is performed by obtaining a draw-down andmeasuring visually by comparison with standard ASTM pictures. Surfacetension can be measured using AccuDyne Marking Pens. Stormer Viscositycan be measured on a Brookfield Viscometer by ASTM method D-562 andreported in Kreb units (Ku).

Any writable-erasable product described herein can have any one or moreof any of the attributes described herein. For example, thewritable-erasable surface can have an average surface roughness (R_(a))of less than about 7,500 nm, a maximum surface roughness (R_(m)) of lessthan about 7,500 nm, a 60 degree gloss of less than about 50 and acontact angle of less than about 100 degrees.

Any coatings described herein can have any one or more of any of thefollowing attributes. For example, the coating can have a porosity ofless than about 45 percent, an elongation at break of between about 25percent and about 200 percent, and/or a Sward hardness of greater thanabout 3 and a Taber abrasion value of less than about 150 mg/thousandcycles.

Formulations

Water-based coatings, predominantly used in architectural settings,contain binders, pigments, solvents, and/or additives. Some of thepolymer systems used in the water-based coatings realm are the acrylicemulsions and urethane dispersions. Water-based coatings presentpotential advantages in terms of reduced odor during curing and containlower VOCs compared to solvent-based coatings. It is also possible toformulate water-based coatings containing none of the chemicalscurrently classified as hazardous air pollutants (HAPs). The coatingformulations, in general, can include either a one-component system or atwo-component system. When the coating is formulated as a one-componentsystem, the coating can be formed from one or more materials, each ofthe one or more materials including one or more functional groupsindependently selected from G1, with at least one material of the one ormore materials in a water-based carrier. When the coating is formulatedas a two-component system, the coating can be formed from two or morematerials. The first material can include one or more functional groupsindependently selected from G1 and the second material can include oneor more functional groups independently selected from G2, with at leastone material of the one or more materials in a water-based carrier. EachG1 functional group in either the one-component or two-component systemis independently selected from among isocyanate, epoxide, urethane,ethyleneoxy, and ethylene, wherein the ethylene is optionallysubstituted with hydroxyl, acetoxy, or alkoxycarbonyl. Each G2functional group in the two-component system is independently selectedfrom among hydroxyl, amine, phenol, carboxylic acid, acid anhydride,aziridine, and thiol. Although water is the predominant carrier,water-based coatings can contain less than about 15% of non-aqueoussolvents to abet in film forming capabilities.

Polyurethanes

Polyurethanes can be obtained by the reaction of a diisocyanate orpolyisocyanate with a diol, or a polyol. Polyurethanes exhibit a widerange of hardness and flexibility depending on various componentsincluding the nature of the isocyanate and/or the polyol in addition tothe nature of curing. Polyurethane coatings could either be formulatedas one component or two component coatings. Reactive polyurethanecoatings involve the isocyanate as the reactive group during curing.See: The ICI Polyurethanes Book, George Woods. (John Wiley & Sons: NewYork, 1987), and Organic Coatings-Properties, Selection and Use U.S.Department of Commerce, National Bureau of Standards: Washington D.C.,Series 7; February 1968, the complete disclosures of which areincorporated by reference herein. Polyurethane coatings have also beencategorically assigned several ASTM designations (Types I-VI).

The coating 14 can be formed from one or more materials includingdiisocyanate (G1=isocyanate) and one or more materials includinghydroxyl (G2=hydroxyl), at least one of these materials being in awater-based carrier. In some implementations, the coating can be orincludes a reaction product of a first component that includes anisocyanate and a second component that includes a polyol. Diisocyanatesfor use in polyurethane applications, in general, can be obtained by thereaction of amines with phosgene. Examples of organic diisocyanatesinclude aliphatic, cycloaliphatic (alicyclic), and aromaticdiisocyanates. e.g., methylene diisocyanate, tetramethylenediisocyanate, hexamethylene diisocyanate (HDI), octamethylenediisocyanate, decamethylene diisocyanate,2-methylpentane-1,5-diisocyanate, toluene diisocyanate (TDI),diphenylmethane diisocyanate (MDI), m- and p-phenylene diisocyanates,4-chloro-m-phenylene diisocyanate, bitolylene diisocyanate, cyclohexanediisocyanate (CHDI), bis-(isocyanatomethyl)cyclohexane (H6XDI),dicyclohexylmethane diisocyanate (H12MDI), dimer acid diisocyanate(DDI), trimethyl hexamethylene diisocyanate, lysine diisocyanate and itsmethyl ester, methyl cyclohexane diisocyanate, 1,5-napthalenediisocyanate, xylene diisocyanate, polyphenylene diisocyanates,isophorone diisocyanate (IPDI), hydrogenated methylene diphenylisocyanate (HMDI), tetramethyl xylene diisocyanate (TMXDI),4-t-butyl-m-phenylenediisocyanate, 4,4′-methylene bis(phenylisocyanate), tolylene diisocyanate, 4-methoxy-m-phenylene diisocyanate,biphenylene diisocyanate, cumene-2,4-diisocyanate,3,3′-dimethyl-4,4′-biphenylene diisocyanate, p,p′-diphenylenediisocyanate, or oligomers and homopolymers thereof, and mixturesthereof. In some embodiments, the aliphatic diisocyanate, theiroligomeric prepolymers, or aliphatic polyisocyanate can be hydrophilic.

The monomeric diisocyanates may further be converted into oligomericprepolymers of higher molecular weight by treatment with diols ortriols. Such oligomeric prepolymers can also be used as a reactioncomponent in the production of the polyurethane coating. Diisocyanatesfor use in polyurethane applications can be available from variouscommercial vendors under different trade names. Examples of commercialdiisocyanates include, but are not limited to, diphenylmethanediisocyanate (MDI) containing Isonate™, Papi™, Spectrim™ (available fromDow chemical company), Desmodur® polyisocyanates and Bayhydur®(available from Bayer), Sovermol® (available from Cognis), Reafree®, andChempol® (both available from Cook Composite Polymers)

In some implementations, the percentage weight of homopolymer ofaliphatic diisocyanate in the total material formulation can be about31%, e.g., about 26%, about 27%, about 28%, about 29%, about 30%, about31%, about 32%, about 33%, about 34%, or even about 35%. In someimplementations, the percentage weight of homopolymer of aliphaticdiisocyanate in the total material formulation can be from about 20% toabout 40%, e.g., from about 22% to about 38%, from about 24% to about36%, from about 26% to about 34%, or from about 28% to about 32%.

The isocyanate containing material of the formulation can have aviscosity of about 91 Kreb Units (Ku), e.g., about 85 Ku, about 90 Ku,about 95 Ku, about 100 Ku, or about 105 Ku. In some implementations, theisocyanate containing material of the formulation can have a viscosityof from about 40 Ku to about 140 Ku, e.g., from about 60 Ku to about 105Ku, from about 70 Ku to about 105 Ku, or from about 80 Ku to about 95Ku.

The polyurethane coatings can also contain polyurethane resins(G1=urethane). In some implementations, the polyurethane resins can bein the form of dispersions of urethane prepolymers and oligomers in awater-based carrier. In some implementations, the polyurethanedispersions can be formulated as either one component or two componentcoatings.

Epoxies

An epoxy coating formulation can be obtained by mixing an epoxy resinwith a curing agent. The epoxy resins are polyether chains that containone or more epoxide units in their structure. Polyethers have therepeating oxyalkylene units: alkylene substituted by oxygen groups,e.g., ethyleneoxy, —[CH₂—CH₂O]—. In some implementations, the polyetherchains can have additional functional groups such as hydroxyl (—OH).Curing of epoxy resins can lead to less amount of volatile products. Dueto the unique properties of the epoxide ring structure, the curingagents can be either nucleophilic or electrophilic. Nucleophilic agentssuch as alcohols, phenols, amines, amino silanes, thiols, carboxylicacids, and acid anhydrides can be used. In some implementations, thesecuring agents can contain one or more nucleophilic groups. The epoxyresins themselves can contain an aliphatic (such as, cyclic or acyclic),aromatic backbone or a combination of both. In some optionalimplementations, the epoxy resins can contain other non-interferingchemical linkages (such as alkyl chains).

The coating 14 can be formed from a epoxy material (G1=epoxide) and ahydroxyl or an amine material, at least one of these materials being ina water-based carrier. In some implementations, the material can be orincludes a reaction product of a first component that includes anepoxide or oxirane material (such as an epoxy prepolymer) in awater-based carrier and a second component that includes an alcohol, analkyl amine (such as, cyclic or acyclic), a polyol, a polyamine (such asisophoronediamine), a polyester polyamine, or an amido polyamine in awater-based carrier. In such implementations, the epoxide or oxiranematerial can serve as a crosslinking material. In some specificimplementations, the epoxide material can be epichlorohydrin, glycidylether type (such as diglycidyl ether of bisphenol-A), oxirane modifiedfatty acid ester type, or oxirane modified ester type. In some specificimplementations, the polyol material can be a polyester polyol,polyamine polyol, polyamide polyol, or amine adduct polyol. In someimplementations, the epoxy coating can be formulated as either onecomponent or two component coatings.

Acrylics

Polyacrylates have the repeating units of ethylene substituted byalkoxycarbonyl groups: —[CH₂—CH(X)]—, where X is alkylOC(O)—. Acrylicemulsions have found applications in water-borne coatings. The acrylicemulsions can include dispersions of acrylic monomers with across-linking catalyst; acrylic copolymers which are capable ofself-crosslinking; styrene acrylic copolymers; or functionalized acryliccopolymers.

In some optional implementations, the material can be or includes anacrylic material in a water-based carrier. In such implementations, theacrylic material can be methyl methacrylate based, butyl acrylate based,ethyl acrylate based, or their mixtures. In such implementations, anpolycarbodiimide, an aziridine, or an imidazoline material can serve asan external crosslinking material. In such implementations, the acryliccoating can be formulated as a one or a two component system.

Vinylic Polymers

Aqueous dispersions of the acrylic vinylic copolymers form the corematerial of this type of formulations. The copolymerization of thepolyvinyl acetate with ethylene provides varying flexibility andtransparency required in many coatings. Polyvinyl acetate has therepeating units of ethylene substituted by acetoxy groups:—[CH₂—CH(X)]—, where X is CH₃C(O)O—, an acetate. Polyethylene has therepeating units of ethylene: —[CH₂—CH₂]—. In some implementations, thematerial can be or includes an vinyl resin material in a water-basedcarrier. In such implementations, the vinylic material can be polyvinylacetate, polyvinyl acetate-ethylene copolymer, polyvinyl alcohol(—[CH₂—CH(X)]—, where X is OH) or a thio functionalized vinyliccopolymer. In such implementations, the material can be a one componentsystem.

Hybrid Systems

Some or all of the formulation systems mentioned above may be combinedtogether to form a hybrid system. The hybrid systems can either be ahybrid copolymer system in a homogeneous medium or a hybrid dispersion.Hybrid dispersions contain two chemical classes which interactcooperatively to provide desired properties, typically in a water-basedcarrier. In some implementations, the material can be a one or a twocomponent hybrid material in a water-based carrier. In suchimplementations, the hybrid material can be a combination ofpolyurethane/acrylic, epoxy/acrylic, alkyd/acrylic, or polyvinylalcohols. In such implementations, an external crosslinker can includean polycarbodiimide, an aziridine, or an imidazoline.

In some implementations, the material can be a one component hybridmaterial in a water-based carrier. In such implementations, the hybridmaterial can be a combination of polyurethane dispersion (PUD)/acrylic,polyvinyl acetate/acrylic, polyvinyl acetate/epoxy, polyvinylacetate/polyurethane, or polyvinyl alcohols. In such implementations, anexternal crosslinker can include an polycarbodiimide, an aziridine, oran imidazoline.

Polyols

An acrylic polyol is an example of a polyol that can be reacted with thereactive groups such as isocyanates, epoxides and other such reactivegroups to produce the coatings. Acrylic polyols can be typicallyobtained by polymerization (free-radical mediated) of hydroxyacrylatesand styrene. Examples of hydroxyacrylates include butanediolmonoacrylate (BDMA), 2-hydroxyethyl acrylate (HEA), 2-hydroxypropylacrylate (HPA), hydroxybutyl acrylate, polycaprolactone modifiedhydroxyethyl hexylacrylate. In some implementations, the percentageweight of acrylic polyol in the total material formulation can be about16%, e.g., about 12%, about 13%, about 14%, about 15%, about 17%, oreven about 18%. In some implementations, the percentage weight ofacrylic polyol in the total material formulation can be from about 10%to about 20%, e.g., from about 11% to about 19%, from about 12% to about18%, from about 13% to about 17%, or from about 14% to about 16%.

A polyoxyalkylene diol is an example of another polyol that can be usedto produce the coatings. In some implementations, the polyoxyalkylenediols have a number average molecular weight of from about 200 to 3,000,e.g., from about 500 to about 2,000, as determined using narrow dispersepolyethylene glycol standards. Specific examples of polyoxyalkylenediols include polyethyleneether glycol, polypropyleneether glycol,polybutyleneether glycol, polytetramethyleneether glycol, and copolymersof polypropyleneether and polyethyleneether glycols. Mixtures of any ofthe polyoxyalkylene diols can also be used.

Polyester polyols or polyester diols are polyesters having terminalhydroxyl groups and are examples of polyols that can be used to producethe coatings. Such polyester diols can be prepared by the condensationof a diol, such as ethylene glycol, propanediol-1,2, propanediol-1,3,butanediol-1,3, butanediol-1,4, pentanediol-1,2, pentanediol-1,5,hexanediol-1,3, hexanediol-1,6, diethylene glycol, dipropylene glycol,triethylene glycol, tetraethylene glycol, or mixtures of these diols,with a dicarboxylic acid or an equivalent thereof, e.g., acid halide oranhydride. Examples of acids include oxalic, malonic, succinic,glutaric, adipic, pimelic, suberic, azelaic, terephthalic, sebacic,malic, phthalic, cylohexanedicarboxylic or mixtures of these acids. Whenpreparing these polyester diols, generally an excess of the diol overdicarboxylic acid is used.

Polyamide diols or polyamide polyols having terminal hydroxyl groups areyet another example of a polyol that can be used to produce thecoatings.

Polyamine polyols having terminal hydroxyl groups are yet anotherexample of a polyol that can be used to produce the coatings.

Polyepoxy polyol having terminal hydroxyl groups are yet another exampleof a polyol that can be used to produce the coatings.

Polyvinyl polyol having terminal hydroxyl groups are yet another exampleof a polyol that can be used to produce the coatings.

A polyurethane diol, having terminal hydroxyl groups is yet anotherexample of a polyol that can be used to produce the coatings. Thepolyurethane diols can include polyalkylene, poly(oxyalkylene),polyester, polyamide, polycarbonate, polysulfide, polyacrylate,polymethacrylate, or mixtures of any of these functionalities along itsbackbone. In some implementations, the polyurethane diols have a numberaverage molecular weight of from about 200 to 3,000, e.g., from about500 to about 2,000, as determined using narrow disperse polyethyleneglycol standards. Polyurethane diols can be advantageously utilized toprovide particularly wear and scratch resistant coatings. Thepolyurethane having terminal hydroxyl groups can be prepared by areaction of any one or more of the polyols discussed above and anorganic diisocyanate to provide a isocyanate terminated prepolymer,followed by reaction of the prepolymer with a polyhydric alcoholcontaining 2-6 hydroxyl groups. Some polyurethane diols are commerciallyavailable from Sigma-Aldrich chemicals or King industries.

The diol can be reacted with the diisocyanate utilizing a molar ratio ofabout 1:2, respectively, in the presence of an activator (oraccelerator) such as oxazolidine or an organotin compound, e.g.,dibutyltin dilaurate or dibutyltin dioctoate. The reaction can beallowed to proceed at a temperature of from about 60° C. to about 180°C., from about 4 hours to about 24 hours to provide the isocyanateterminated prepolymer.

The isocyanate terminated urethane prepolymer can then be reacted, e.g.,at from about 60° C. to about 110° C. for 1 to about 10 hours, with amonomeric, polyhydric alcohol containing 2-6 hydroxyl groups in a molarratio of 1:2, respectively. Examples of alcohols that can be usedinclude 1,4-cyclohexane dimethanol, 1,4-butanediol, mannitol,trimethylol propane, trimethylol ethane, 1,1-cyclohexane dimethanol,hydrogenated bisphenol A, cyclohexane diol, neopentyl glycol,trimethylpentanediol, pentaerythritol, and trimethylhexanediol. Theresult of treating the isocyanate terminated urethane prepolymer withthe one or more alcohols is a polyurethane diol having 2-10 terminalhydroxyl groups and no isocyanates groups.

Polyurethane diols can also be made by reacting organic carbonates withamines.

In some implementations in which a polyurethane diol is used to make thecoating, the molar proportion of polyurethane diol to thealkoxyalkylamino material can range from about 10:1 to about 1:1, e.g.,5:1 to 1:1.

Examples of commercial polyols include, but are not limited to,Desmophen® (available from Bayer), Macrynal® (available from CytecIndustries), and Arolon® (available from Reichold).

In some implementations, the material can include an externalcrosslinker, such as a polycarbodiimide, an aziridine, or animidazoline.

Other Implementations:

In some optional implementations, the material can be or includes areaction product of a first component that includes an alkoxyalkylaminomaterial in a water-based carrier and a second component that includes apolyol in a water-based carrier. In such implementations, thealkoxyalkylamino material can serve as a crosslinking material.

In yet other optional implementations, the material can be or includesan alkyd material in a water-based carrier. In such implementations, theoil part of the material can be castor oil, soybean oil, sunflower oil,soya oil, linseed oil, or their mixtures. In such implementations, thematerial can be a one or a two component system.

In yet other optional implementations, the material can be selected fromfluorine based resins or silica based resins. In such implementations,the material can be a one or a two component system.

In yet other optional implementations, the material can be selected froma rosin phenolic, an epoxy ester, polyurea, polyaspartics, or adipicdihydrazine based. In such implementations, the material can be a twocomponent system.

Solvents

The coating 14 can be formed from a material in a water-based carrier.While not intending to be bound by theory, it is believed that solventscan be effective as a dispersive vehicle for the pigments and resins ina coating formulation prior to curing. During the application of theformulation, they aid in achieving an appropriate viscosity of theformulation. However, after the coating has been cured, it can beexpected that there is no residual solvent. The solvents can include2-butoxyethanol, ethylene glycol, ethyl benzene, xylenes, methyl amylketone, isopropyl alcohol, propylene glycol monomethyl ether, ethyleneglycol monobutyl ether, butanol, paraffins, alkanes, polypropyleneglycol, Stoddard solvent, toluene, ethoxylated alkylphenol,1-methyl-2-pyrrolidinone, or 1-ethylpyrrolidin-2-one.

Other Modifying Agents in the Formulations

Accelerators that can be used in the formulation include catalysts suchas dibutyltin dialkanoate (e.g., dibutyltin dialaurate, dibutyltindioctoate), and oxazolidine. Acid promoters include sulfonic acids,e.g., aryl, alkyl, and aralkyl sulfonic acids; aryl, alkyl, and aralkylphosphoric and phosphonic acids; aryl, alkyl, and aralkyl acidpyrophosphates; carboxylic acids; sulfonimides; mineral acids andmixtures thereof. In some implementations, phosphoric acid can beutilized. Examples of sulfonic acids include benzenesulfonic acid,para-toluenesulfonic acid, dodecylbenzenesulfonic acid, andnaphthalenesulfonic acid. Examples of aryl, alkyl, and aralkylphosphates and pyrophosphates include phenyl, para-tolyl, methyl ethyl,benzyl, diphenyl, di-para-tolyl, di-methyl, di-ethyl, di-benzyl,phenyl-para-tolyl, methyl-ethyl, phenyl-benzyl phosphates andpyrophosphates. Examples of carboxylic acids include benzoic acid,formic acid, acetic acid, propionic acid, butyric acid, dicarboxylicacids such as oxalic acid, and fluorinated acids such as trifluoroaceticacid. Examples of sulfonimides include dibenzene sulfonimide,di-para-toluene sulfonimide, methyl-para-toluene sulfonimide, anddimethyl sulfonamide. Examples of mineral acids include nitric acid,sulfuric acid and hydrochloric acid.

The curable compositions can also contain other optional ingredientssuch as fillers, surfactants, light stabilizers, pigments, opacifyingagents, defoaming agent, surface gloss-modifying agent, biocides, aviscosity-modifying agent, dispersing agents, reactive diluents,extender pigments, inhibitors for corrosion or efflorescence, flameretardants, intumescent agents, thermal agents for energy efficiency,additives for protection from UV and/or IR, self-cleaning agents,perfumes, or odor sustaining agents.

Several commercial suitable light stabilizers are available from CIBASpecialty Chemicals under the trade names Tinuvin® (benzotriazole,triazine, or hindered amine based) and Chimassorb® (benzophenone based).

Examples of opacifying agents zinc oxide, titanium dioxide, silicondioxide, Kaolin clay, e.g., high whiteness Kaolin clay, or mixturesthereof.

Examples of defoaming agents include polyethylene glycols, or siliconesurfactants, e.g., polyether modified polydimethyl siloxane. Defoamingagents such as BYK family of agents are available from BYK-Chemie GmbH.

Examples of viscosity modifying agents include polyurethanes, orTafigel®, a commercial acrylic copolymer available from Munzing ChemieGmbH.

Certain implementations are further described in the following examples,which are not intended to limit the scope of the disclosure.

EXAMPLES Example 1

First Component:

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 1: oxirane-modified fatty acid ester,Stoddard solvent, butyl glycolate, 2-butoxyethanol, alkylarylalkoxylate, ester/styrene maleic anhydride copolymer, ethylene glycol,2,4,7,9-tetramethyl-5-decyne-4,7-diol, ethyl benzene and xylene (mixedisomers). The contents were then mixed at slow speeds until fullydispersed. The speed was maintained at no more than 100-200 rpm.Titanium dioxide, aluminum hydroxide, amorphous silica and water werethen added to the mixture in the pot, while increasing the speed toachieve a good vortex. Final RPM settings were between 2,000-3,000 rpm.The speed was adjusted until maximum shear was obtained with minimalintegration of air and mixed for 10-15 minutes, or a Hegman of 5-6.After ascertaining that there were no chunks, the speed was increased toachieve sufficient vortex. A sufficient RPM was maintained while keepingthe temperature in the pot below 95-110° F. Hegman at this point was atleast a 7. Once Hegman was achieved, mixing speed was reduced until thepot was just mixing the raw materials and continued for 10-15 minutes.

During the letdown stage, propylene glycol monomethyl ether, methyl amylketone and isopropyl alcohol were added to the grind mixture. The speedwas maintained to mix the material. After 15-20 minutes the product waspackaged.

Second Component:

The high acid value polyester, ethylene glycol monobutyl ether andisopropyl alcohol mixture was the second component of the final product.No mixing was required for these materials.

Combining the First and Second Components:

The first and second components were combined, when desired, to obtainthe final coating formulation. The combination had a pot life of amaximum of about 1 hour during which time the application was completed.The composition of the formulation is described in Table 1.

TABLE 1 Epoxy and alcohol based formulation range % by wt on totalComponent formula oxirane-modified fatty acid ester 17-20 stoddardsolvent 0.10-0.14 butylglycolate 0.005-0.02  2-butoxyethanol 0.001-0.006alkylarylalkoxylate 0.02-0.13 ester/styrene maleic anhydride copolymer0.01-0.10 ethylene glycol 0.01-0.032,4,7,9-tetramethyl-5-decyne-4,7-diol 0.01-0.03 ethyl benzene 0.04-0.07xylenes 0.4-0.6 titanium dioxide 13-15 aluminum hydroxide 1-3 amorphoussilica 1-3 water 4-6 propylene glycol monomethyl ether 1-3 methyl amylketone 5-7 isopropyl alcohol 3-6 high acid value polyester 20-23ethylene glycol monobutyl ether 4-6 isopropyl alcohol 4-6

Example 2

First Component:

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 2: water, polyetherpolysiloxane,polyalkylene oxide, alkylarylalkoxylate, ester/styrene maleic anhydridecopolymer, ethylene glycol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol,2-butoxyethanol, polypropylene glycol and polysiloxanes. The contentswere then mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, methyl benzimidazole-2-yl carbamate, Koalin,3-iodo-2-propynyl butyl carbamate, synthetic fatty acids modifiedacrylic copolymer and butanol, were added to the grind mixture. Thespeed was maintained to mix the material. After 15-20 minutes theproduct was packaged.

Second Component:

The mixture of N,N-dimethylcyclohexylamine,hexamethylene-1,6-diisocyanate and hydrophilic aliphatic polyisocyanatebased on hexamethylene diisocyanate was the second component of thefinal product. No mixing was required for these materials.

Combining the First and Second Components:

The first and second components were combined, when desired, to obtainthe final coating formulation. The combination had a pot life of amaximum of about 1 hour during which time the application was completed.The composition of the formulation is described in Table 2.

TABLE 2 Isocyanate with acrylic polyol based formulation Range % by wton Component total formula water 19-24 polyetherpolysiloxane 0.008-0.012polyalkylene oxide 0.004-0.006 alkylarylalkoxylate 0.12-0.36ester/styrene maleic anhydride copolymer 0.15-0.40 ethylene glycol0.04-0.12 2,4,7,9-tetramethyl-5-decyne-4,7-diol 0.04-0.082-butoxyethanol 0.006-0.010 polypropylene glycol 0.90-1.00 polysiloxanes0.036-0.041 titanium dioxide 21-23 aluminum hydroxide 1-3 amorphoussilica 1-3 methyl benzimidazole-2-yl carbamate 0.07-0.09 koalin0.07-0.09 3-iodo-2-propynyl butyl carbamate 0.03-0.05 synthetic fattyacids modified acrylic copolymer 23-29 butanol 1.9-2.1N,N-dimethylcyclohexylamine 1.5-1.7 hexamethylene-1,6-diisocyanate0.17-0.19 hydrophilic aliphatic polyisocyanate based on 32-36hexamethylene diisocyanate

Example 3

First Component:

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 3: water, polyetherpolysiloxane,polyalkylene oxide, alkylarylalkoxylate, ester/styrene maleic anhydridecopolymer, ethylene glycol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol,2-butoxyethanol, polypropylene glycol and polysiloxanes. The contentswere then mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, 2-amino-2-methyl-1-propanol,2-(methylamino)-2-methyl-1-propanol, methyl benzimidazole-2-ylcarbamate, Koalin and 3-iodo-2-propynyl butyl carbamate were added tothe grind mixture. After less than 5-10 minutes, synthetic fatty acidsmodified acrylic copolymer and butanol were added to the pot. The speedwas maintained to mix the material. After 15-20 minutes the product waspackaged.

Second Component:

The mixture of homopolymer of hexane-1,6-diisocyanate, n-butyl acetate,polyoxyethylene tridecyl ether phosphate, N,N-dimethyl-cyclohexanamine,1,6-diisocyanato-hexane and isophorone diisocyanate was the secondcomponent of the final product. No mixing was required for thesematerials.

Combining the First and Second Components:

The first and second components were combined, when desired, to obtainthe final coating formulation. The combination had a pot life of amaximum of about 1 hour during which time the application was completed.The composition of the formulation is described in Table 3.

TABLE 3 Isocyanate based formulation containing IPDI Range % by wt onComponent total formula water 19-24 polyetherpolysiloxane 0.008-0.012polyalkylene oxide 0.004-0.006 alkylarylalkoxylate 0.12-0.36ester/styrene maleic anhydride copolymer 0.15-0.40 ethylene glycol0.04-0.12 2,4,7,9-tetramethyl-5-decyne-4,7-diol 0.04-0.082-butoxyethanol 0.006-0.010 polypropylene glycol 0.90-1.00 polysiloxanes0.036-0.041 titanium dioxide 21-23 aluminum hydroxide 1-3 amorphoussilica 1-3 2-amino-2-methyl-1-propanol 0.05-0.072-(methylamino)-2-methyl-1-propanol 0.003-0.005 methylbenzimidazole-2-yl carbamate 0.07-0.09 koalin 0.07-0.093-iodo-2-propynyl butyl carbamate 0.03-0.05 synthetic fatty acidsmodified acrylic copolymer 23-29 butanol 1.9-2.11,6-diisocyanato-hexane, homopolymer 16-18 n-butyl acetate 4.5-7.5polyoxyethylene tridecyl ether phosphate 2-4N,N-dimethyl-cyclohexanamine 0.65-0.75 1,6-diisocyanato-hexane 0.08-0.09isophorone diisocyanate 0.08-0.09

Example 4

First Component:

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 4: water, poly amine adduct,tetraethylenepentamine, a mixture of polymers and hydrophobic polymers,2-ethyl-1hexanol, paraffins, and modified polyacrylate. The contentswere then mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, alkanes, 2-butoxyethanol and ethoxylatedalkylphenol were added to the grind mixture. The speed was maintained tomix the material. After less than 5-10 minutes, acrylic nonioniccopolymer and 2-methoxymethylethoxy-propanol were added to the pot. Thespeed was maintained to mix the material. After less than 5-10 minutes,solution of modified urea, 1-methyl-2-pyrrolidone and lithium chloridewere added to the pot. The speed was maintained to mix the material.After less than 5-10 minutes, polysiloxane and polyethylene glycol wereadded to the pot. The speed was maintained to mix the material. After15-20 minutes the product was packaged.

Second Component:

The diglycidyl ether of bisphenol-A homopolymer mixture was the secondcomponent of the final product. No mixing was required for thesematerials.

Combining the First and Second Components:

The first and second components were combined, when desired, to obtainthe final coating formulation. The combination had a pot life of amaximum of about 1-2 hours during which time the application wascompleted. The composition of the formulation is described in Table 4.

TABLE 4 Epoxy and amine based formulation Range % by wt on totalComponent formula water 27-32 poly amine adduct 6-7tetraethylenepentamine 0.40-1.00 mixture of polymers and hydrophobicpolymers 0.018-0.021 2-ethyl-1-hexanol 0.0015-0.0025 paraffins0.040-0.050 modified polyacrylate 0.01-0.50 titanium dioxide 12-16aluminum hydroxide 1-2 amorphous silica 1-2 alkanes 0.48-0.802-butoxyethanol 0.040-0.085 ethoxylated alkylphenol 0.008-0.041 acrylicnonionic copolymer 0.11-0.13 2-methoxymethylethoxy-propanol 0.07-0.14modified urea 0.035-0.038 1-methyl-2-pyrrolidone 0.020-0.045 lithiumchloride 0.0005-0.0010 polysiloxane 0.01-0.10 polyethylene glycol0.01-0.10 diglycidyl ether of bisphenol-A homopolymer 49-51

Example 5

First Component:

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 5: water, xylene, polypropylene glycol,polysiloxanes, functionalized polyacrylate copolymer, alkanes,2-butoxyethanol and ethoxylated alkylphenol. The contents were thenmixed at slow speeds until fully dispersed. The speed was maintained atno more than 100-200 rpm. Titanium dioxide, aluminum hydroxide,amorphous silica and water were added to the mixture in the pot, whileincreasing the speed to achieve a good vortex. Final RPM settings werebetween 2,000-3,000 rpm. The speed was adjusted until maximum shear wasobtained with minimal integration of air and mixed for 10-15 minutes, ora Hegman of 5-6. After ascertaining that there were no chunks, the speedwas increased to achieve sufficient vortex. A sufficient RPM wasmaintained while keeping the temperature in the pot below 95-110° F.Hegman at this point was at least a 7. Once Hegman was achieved, mixingspeed was reduced until the pot was just mixing the raw materials andcontinued for 10-15 minutes.

During the letdown stage, 2-amino-2-methyl-1-propanol and2-(methylamino)-2-methyl-1-propanol were added to the grind mixture.After less than 5-10 minutes, N,N-diethylethanamine, polyurethane resinand 1-methyl-2-pyrrolidinone were added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,fluoroaliphatic polymeric esters+(5049P), residual organicfluorochemicals, toulene and fluorochemical monomers were added to thepot. The speed was maintained to mix the material. After less than 5-10minutes polyurethane resin was added to the pot. After less than 5-10minutes, polyurethane resin was added to the pot. The speed wasmaintained to mix the material. After 15-20 minutes the productpackaged.

Second Component:

The polyfunctional aziridine mixture was the second component of thefinal product. No mixing was required for these materials.

Combining the First and Second Components:

The first and second components were combined, when desired, to obtainthe final coating formulation. The combination had a pot life of amaximum of about 1 hour during which time the application was completed.The composition of the formulation is described in Table 5.

TABLE 5 Polyurethane based formulation Range % by wt on total Componentformula water 55-60 xylene 0.0025-0.0035 polypropylene glycol 0.14-0.29polysiloxanes 0.54-0.56 functionalized polyacrylate copolymer 0.25-0.26alkanes 0.11-0.19 2-butoxyethanol 1.49-1.54 ethoxylated alkylphenol0.002-0.010 titanium dioxide 19-24 aluminum hydroxide 1-2 amorphoussilica 1-3 2-amino-2-methyl-1-propanol 0.15-0.172-(methylamino)-2-methyl-1-propanol  0.08-0.010 N,N-diethylethanamine0.40-1.00 polyurethane resin 13-15 1-methyl-2-pyrrolidinone 7-8fluoroaliphatic polymeric esters + (5049p) 0.13-0.15 residual organicfluorochemicals 0.0040-0.0045 toluene 0.0020-0.0025 fluorochemicalmonomer 0.0015-0.0020 polyurethane resin 0.09-0.010 polyurethane resin0.39-0.44 polyfunctional aziridine 0.64-0.67

Example 6

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 6: water, propylene glycol, xylene,polypropylene glycol, polysiloxanes, polycarboxylate-sodium salt,alkanes, 2-butoxyethanol and ethoxylated alkylphenol. The contents werethen mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, vinyl acetate/ethylene copolymer was added tothe grind mixture. After less than 5-10 minutes,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was added to the pot.The speed was maintained to mix the material. After less than 5-10minutes, polyurethane resins and enzymatically modified starch wereadded to the pot. The speed was maintained to mix the material. After15-20 minutes the product was packaged. The composition of theformulation is described in Table 6.

TABLE 6 Vinyl acetate-ethylene based formulation Range % by wt on totalComponent formula water 44-54 propylene glycol 0.60-0.70 xylene0.02-0.03 polypropylene glycol 1.00-2.00 polysiloxanes 0.30-0.40polycarboxylate, sodium salt 0.42-0.47 alkanes 0.74-1.23 2-butoxyethanol0.06-0.12 ethoxylated alkylphenol 0.01-0.06 titanium dioxide 24-30aluminum hydroxide 1-3 amorphous silica 1-4 vinyl acetate/ethylenecopolymer 17-25 2,2,4-trimethyl-1,3-pentanediol 1-2 monoisobutyratepolyurethane resin 0.29-0.36 polyurethane resin 0.16-0.20 enzymaticallymodified starch 0.04-0.06

Example 7

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 7: water, N,N-diethylethanamine,polyurethane resin, 1-methyl-2-pyrrolidinone, alkanes, 2-butoxyethanoland ethoxylated alkylphenol. The contents were then mixed at slow speedsuntil fully dispersed. The speed was maintained at no more than 200-400rpm. There was no Hegman grind to measure in this formula. Once blendingwas achieved, mixing speed was reduced until the pot was just mixing theraw materials and continued for 10-15 minutes. The speed was maintainedto mix the material. After 15-20 minutes the product was packaged. Thecomposition of the formulation is described in Table 7.

TABLE 7 Polyurethane (oil modified) based formulation Range % by wt ontotal Component formula water 63-65 N,N-diethylethanamine 1-2polyurethane resin 29-30 1-methyl-2-pyrrolidinone 3.8-5.7 alkanes0.60-1.00 2-butoxyethanol 0.05-0.10 ethoxylated alkylphenol 0.01-0.05

Example 8

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 8: water,chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one,magnesium chloride, magnesium nitrate, polycarboxylate-sodium salt,ammonium hydroxide,α-(phenylmethyl)-ω-(1,1,3,3,-tetramethylbutyl)phenoxypoly(oxy-1-2-ethanediyl), mono{(1,1,3,3-tetramethylbutyl)phenyl}etherpolyethylene glycols, xylene and polysiloxanes. The contents were thenmixed at slow speeds until fully dispersed. The speed was maintained atno more than 100-200 rpm. Titanium dioxide, aluminum hydroxide,amorphous silica and water were added to the mixture in the pot, whileincreasing the speed to achieve a good vortex. Final RPM settings werebetween 2,000-3,000 rpm. The speed was adjusted until a maximum shearwas obtained with minimal integration of air and mixed for 10-15minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, acrylic monomers were added to the grindmixture. After less than 5-10 minutes, 2,2,4-trimethyl-1,3-pentanediolmonoisobutyrate was added to the pot. The speed was maintained to mixthe material. After less than 5-10 minutes, polyurethane resin and2-butoxyethanol were added to the pot. The speed was maintained to mixthe material. After less than 5-10 minutes polyethylene glycoloctylphenyl ether and poly(ethylene oxide) were added to the pot. Thespeed was maintained to mix the material. After less than 5-10 minutes,propylene glycol was added to the pot. The speed was maintained to mixthe material. After less than 5-10 minutes, polyurethane resin was addedto the pot. The speed was maintained to mix the material. After 15-20minutes the product was packaged. The composition of the formulation isdescribed in Table 8.

TABLE 8 Acrylic emulsion based formulation Range % by wt on Componenttotal formula Water 53-60 chloro-2-methyl-4-isothiazolin-3-one0.00016-0.00020 2-methyl-4-isothiazolin-3-one 0.0004-0.0007 magnesiumchloride 0.001-0.002 magnesium nitrate 0.002-0.003 polycarboxylate,sodium salt 0.11-0.14 ammonium hydroxide 0.025-0.028α-(phenylmethyl)-ω-(1,1,3,3,- 0.080-0.084 tetramethylbutyl)phenoxy-poly(oxy-1-2-ethanediyl) polyethylene glycols, mono{(1,1,3,3-0.013-0.015 tetramethylbutyl)phenyl}ether Xylene 0.1-0.2 Polysiloxanes0.015-0.025 titanium dioxide 17-21 aluminum hydroxide 1-2 amorphoussilica 1-3 acrylic monomers 24-27 2,2,4-trimethyl-1,3-pentanediolmonoisobutyrate 0.74-0.77 polyurethane resin 0.55-0.61 2-butoxyethanol0.26-0.32 Polypropylene glycol 0.10-0.20 polyethylene glycol octylphenylether 0.40-0.43 poly(ethylene oxide) 0.010-0.014 propylene glycol0.55-0.59 polyurethane resin 0.055-0.065

Example 9

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 9: water, xylene, polypropylene glycol,polysiloxanes, functionalized polyacrylate copolymer, alkanes,2-butoxyethanol and ethoxylated alkylphenol. The contents were thenmixed at slow speeds until fully dispersed. The speed was maintained atno more than 100-200 rpm. Titanium dioxide, aluminum hydroxide,amorphous silica and water were added to the mixture in the pot, whileincreasing the speed to achieve a good vortex. Final RPM settings werebetween 2,000-3,000 rpm. The speed was adjusted until maximum shear wasobtained with minimal integration of air and mixed for 10-15 minutes, ora Hegman of 5-6. After ascertaining that there were no chunks, the speedwas increased to achieve sufficient vortex. A sufficient RPM wasmaintained while keeping the temperature in the pot below 95-110° F.Hegman at this point was at least a 7. Once Hegman was achieved, mixingspeed was reduced until the pot was just mixing the raw materials andcontinued for 10-15 minutes.

During the letdown stage, 2-amino-2-methyl-1-propanol and2-(methylamino)-2-methyl-1-propanol were added to the grind mixture.After less than 5-10 minutes, NAN-diethylethanamine, polyurethane resinand 1-methyl-2-pyrrolidinone were added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,fluoroaliphatic polymeric esters+(5049P), residual organicfluorochemicals, toluene and fluorochemical monomer were added to thepot. The speed was maintained to mix the material. After less than 5-10minutes polyurethane resin was added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,polyurethane resin was added to the pot. The speed was maintained to mixthe material. After 15-20 minutes the product packaged. Pot life on themixture was greater than 4 hours but less than 24 hours. The compositionof the formulation is described in Table 9.

TABLE 9 Polyurethane based formulation Range % by wt on total Componentformula Water 55-60 Xylene 0.0025-0.0035 polypropylene glycol 0.14-0.29Polysiloxanes 0.54-0.56 functionalized polyacrylate copolymer 0.25-0.26alkanes 0.11-0.19 2-butoxyethanol 1.49-1.54 ethoxylated alkylphenol0.002-0.010 titanium dioxide 19-24 aluminum hydroxide 1-2 amorphoussilica 1-3 2-amino-2-methyl-1-propanol 0.15-0.172-(methylamino)-2-methyl-1-propanol  0.08-0.010 N,N-diethylethanamine0.40-1.00 polyurethane resin 13-15 1-methyl-2-pyrrolidinone 7-8fluoroaliphatic polymeric esters + (5049p) 0.13-0.15 residual organicfluorochemicals 0.0040-0.0045 toluene 0.0020-0.0025 fluorochemicalmonomer 0.0015-0.0020 polyurethane resin  0.09-0.010 polyurethane resin0.39-0.44

Example 10

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 10: water, polyurethane dispersion, benzylbenzoate, dipropylene glycol butyl ether, tri-n-butyl citrate andpropylene glycol. The contents were then mixed at slow speeds untilfully dispersed. The speed was maintained at no more than 200-400 rpm.There was no Hegman grind to measure in this formula. Once blending wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, andethylene glycol were added to the pot. The speed was maintained to mixthe material. After less than 5-10 minutes, an emulsion oforgano-modified polysiloxanes and α-octadecyl-ω-hydroxypoly(oxy-1,2-ethanediyl), was added to the pot. The speed was maintainedto mix the material. After less than 5-10 minutes, nonionic polyethylenewax was added to the pot. The speed was maintained to mix the material.After 15-20 minutes the product was packaged. The composition of theformulation is described in Table 10.

TABLE 10 Polyurethane dispersion based formulation Range % by wt onComponent total formula Water 15-22 polyurethane resin 68-75 benzylbenzoate 1-3 dipropylene glycol butyl ether 5-7 tri-n-butyl citrate0.73-0.76 propylene glycol 0.90-1.002,4,7,9-tetramethyl-5-decyne-4,7-diol   1-1.1 ethylene glycol 0.34-0.37emulsion of organo-modified polysiloxanes 0.20-0.22α-octadecyl-ω-hydroxy poly(oxy-1,2-ethanediyl) 0.002-0.010 nonionicpolyethylene wax 0.65-0.68

Example 11

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 11: water, propylene glycol, polypropyleneglycol, polysiloxanes, polycarboxylate-sodium salt, alkanes,2-butoxyethanol and ethoxylated alkylphenol. The contents were thenmixed at slow speeds until fully dispersed. The speed was maintained atno more than 100-200 rpm. Titanium dioxide, aluminum hydroxide,amorphous silica and water were added to the mixture in the pot, whileincreasing the speed to achieve a good vortex. Final RPM settings werebetween 2,000-3,000 rpm. The speed was adjusted until maximum shear wasobtained with minimal integration of air and mixed for 10-15 minutes, ora Hegman of 5-6. After ascertaining that there were no chunks, the speedwas increased to achieve sufficient vortex. A sufficient RPM wasmaintained while keeping the temperature in the pot below 95-110° F.Hegman at this point was at least a 7. Once Hegman was achieved, mixingspeed was reduced until the pot was just mixing the raw materials andcontinued for 10-15 minutes.

During the letdown stage, polyurethane/acrylic mixture,1-ethylpyrrolidin-2-one and 2-(2-butoxyethoxy) ethanol were added to thegrind mixture. The speed was maintained to mix the material. After lessthan 5-10 minutes, benzoate esters were added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,polyurethane resin was added to the pot. The speed was maintained to mixthe material. After less than 5-10 minutes, polyurethane resin andenzymatically modified starch were added to the pot. The speed wasmaintained to mix the material. After 15-20 minutes the product waspackaged. The composition of the formulation is described in Table 11.

TABLE 11 Hybrid polyurethane-acrylic dispersion based formulationComponent Range % by wt on total formula water 52-60 propylene glycol0.48-0.50 polypropylene glycol 0.72-1.45 polysiloxanes 0.056-0.060polycarboxylate, sodium salt 0.33-0.36 alkanes 0.56-1.00 2-butoxyethanol0.04-0.10 ethoxylated alkylphenol 0.01-0.05 titanium dioxide 19-24aluminum hydroxide   1-2.5 amorphous silica   1-2.5 polyurethane/acrylicmixture 18-20 1-ethylpyrrolidin-2-one 0.48-2.5  2-(2-butoxyethoxy)ethanol 0.48-2.5  benzoate esters 0.95-1.00 polyurethane resin 0.23-0.26polyurethane resin 0.13-0.16 enzymatically modified starch 0.028-0.049

Example 12

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 12: water, propylene glycol, xylene,polypropylene glycol, polysiloxanes, polycarboxylate-sodium salt,alkanes, 2-butoxyethanol and ethoxylated alkylphenol. The contents werethen mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, acrylic copolymer emulsion was added to thegrind mixture. The speed was maintained to mix the material. After lessthan 5-10 minutes, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate wasadded to the pot. The speed was maintained to mix the material. Afterless than 5-10 minutes, polyurethane resin was added to the pot. Thespeed was maintained to mix the material. After less than 5-10 minutes,polyurethane resin and enzymatically modified starch were added to thepot. The speed was maintained to mix the material. After 15-20 minutesthe product was packaged. The composition of the formulation isdescribed in Table 12.

TABLE 12 Acrylic based formulation Range % by wt on Component totalformula water 50-57 propylene glycol 0.60-0.63 xylene 0.018-0.022polypropylene glycol 0.91-1.90 polysiloxanes 0.33-0.37 polycarboxylate,sodium salt 0.42-0.47 alkanes 0.73-1.25 2-butoxyethanol 0.06-0.13ethoxylated alkylphenol 0.012-0.06  titanium dioxide 24-31 aluminumhydroxide 1-3 amorphous silica 1-3 acrylic copolymer emulsion 17.0-19.52,2,4-trimethyl-1,3-pentanediol monoisobutyrate 1.20-1.30 polyurethaneresin 0.29-0.33 polyurethane resin 0.17-0.20 enzymatically modifiedstarch 0.03-0.07

Example 13

During the grind stage, to the pot were added, in order, in the rangesof weight % listed in Table 13: water, xylene, polypropylene glycol,polysiloxanes, and functionalized polyacrylate copolymers. The contentswere then mixed at slow speeds until fully dispersed. The speed wasmaintained at no more than 100-200 rpm. Titanium dioxide, aluminumhydroxide, amorphous silica and water were added to the mixture in thepot, while increasing the speed to achieve a good vortex. Final RPMsettings were between 2,000-3,000 rpm. The speed was adjusted untilmaximum shear was obtained with minimal integration of air and mixed for10-15 minutes, or a Hegman of 5-6. After ascertaining that there were nochunks, the speed was increased to achieve sufficient vortex. Asufficient RPM was maintained while keeping the temperature in the potbelow 95-110° F. Hegman at this point was at least a 7. Once Hegman wasachieved, mixing speed was reduced until the pot was just mixing the rawmaterials and continued for 10-15 minutes.

During the letdown stage, 2-amino-2-methyl-1-propanol and2-(methylamino)-2-methyl-1-propanol were added to the grind mixture. Thespeed was maintained to mix the material. After less than 5-10 minutes,epoxy based styrene-acrylic copolymer was added to the pot. The speedwas maintained to mix the material. After less than 5-10 minutes,dipropylene glycol monomethyl ether was added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate was added to the pot.The speed was maintained to mix the material. After less than 5-10minutes, polyurethane resin was added to the pot. The speed wasmaintained to mix the material. After less than 5-10 minutes,polyurethane resin and 2-butoxyethanol were added to the pot. The speedwas maintained to mix the material. After 15-20 minutes the product waspackaged. The composition of the formulation is described in Table 13.

TABLE 13 Epoxy-acrylic based formulation Range % by wt on Componenttotal formula Water 51-58 Xylene  0.001-0.0015 polypropylene glycol0.14-0.30 polysiloxanes 0.024-0.030 functionalized polyacrylatecopolymer 0.24-0.27 titanium dioxide 19-24 aluminum hydroxide   1-2.5amorphous silica   1-2.5 2-amino-2-methyl-1-propanol 0.14-0.182-(methylamino)-2-methyl-1-propanol 0.008-0.010 epoxy basedstyrene-acrylic copolymer 21-24 dipropylene glycol monomethyl ether19-22 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate 19.5-22.5Polyurethane resin 0.10-0.11 Polyurethane resin 0.39-0.442-butoxyethanol 0.18-0.24

Example 14 Quantitative Determination of the Erasable Characteristics ofthe Writable-Erasable Surface

The color stimulus, which is the radiation from the colored object thatproduces the perception of that color, can be measured. Color perceptionis affected not only by the spectral make up of the object, but also thelight source under which it is viewed. If the spectral distribution ofthe light source and the relative spectral reflectance of the object areknown, then the spectral composition reaching the eye of an observerwith normal vision from the object illuminated by that source can becalculated. The Commission Internationale de L'Eclairage (CIE) has setup procedures for calculation of the color differences in a CIELAB colorspace. The X-Rite Sp-62 Spectrophotometer can be used to take the colorreadings and it calculates these values automatically. The values canthen be recorded. The changes can then be calculated according to ASTMTest Method D2244, as differences in the L*, a*, and b* values, wherethe direction of the color difference is described by the magnitude andthe algebraic signs of the components, ΔL*, Δa*, Δb*. The values arethen calculated as follows:ΔL*=L* ₁ −L* ₀  (1)Δa*=a* ₁ −a* ₀  (2)Δb*=b* ₁ −b* ₀  (3)where L*₀, a*₀, b*₀ refers to the reference, and L*₁, a*₁, b*₁, refersto the test specimen. Table 14 shows the magnitude and direction of eachcolor value and what color change occurs.

TABLE 14 Meanings of Color Values Direction Color Change Value Result +L* Lighter − L* Darker + A* Redder (less green) − A* Green (less red) +B* Yellow (less blue) − B* Bluer (less yellow)By choosing one sample to be the reference point, the change in colorfrom this reference point is called the color difference (ΔE), which iscalculated from the equation:ΔE=[(ΔL*)²+(Δa*)²+(Δb*)²]^(1/2)  (4)

Example 15 Determination of Erasable Characteristics of aWritable-Erasable Surface

The nature of visual change (erasable characteristics) on thewritable-erasable surface can be evaluated by the visual changeperceived after the surface has been marked followed by erasing themarking. It can be characterized by the leave behind which can bedetermined after 1 or 2 passes by the eraser to erase the marking: themarkings may seem to stick to the surface and they might erase as instreaks or might be spotty. The quality of the surface can also bemeasured by the dirtiness which can be determined after one pass withthe eraser over the marked area, a faint to dark cloud might be leftfrom the eraser, like smearing of the marking due to the eraser. Both“leave behind” and “dirtiness” can be measured on a scale of zero to tenbased on the degree to which the marking material can be removed fromthe surface. The lower number indicates a better surface performance.

Example 16 Application of the Coating

The application is performed in a clean, dustless environment. Prior toinstallation, the ambient temperature within the application site ismaintained at not less than 45° F. for a minimum of 24 hours and properventilation of application areas is ascertained to minimize odors invicinity of application. The surface of the substrate to be painted onis primed, using a non-tinted PVA or vinyl acrylic interior latexprimer, until the color of the existing surface does not show through.The primer is allowed to dry completely according to manufacturer'srecommendation. The surface is painted in approximately 2 foot widesections by working from one end to the other. Each section is completedbefore painting the next section. A wet edge is maintained to avoid lapmarks. A single coat is applied using foam roller covers. The equipmentis cleaned with acetone or denatured alcohol. The coating is allowed tocure for 1 week, at room temperature, to form the writable-erasablesurface.

The writable-erasable surface can be maintained by daily erasure andcleaning with a standard dry-erase eraser or a dry cloth. For periodicand more thorough cleaning, a damp cloth may be used.

If it is desired to clear the writable-erasable surface or recoat anydamaged surface, the original surface is deglossed by sanding thesurface and priming before application of the dry erase coating.

Other Implementations

A number of implementations have been described. Nevertheless, it willbe understood that various modifications can be made without departingfrom the spirit and scope of the disclosure. Accordingly, otherimplementations are within the scope of the following claims.

For example, while rollers have been described for applying thematerials, brushes, pre-loaded applicators, or sprayers can be used.When sprayers are used, the precursor materials can be first mixed andthen sprayed onto a substrate, or the precursor materials can each besprayed from separate nozzle outlet, the mixing of the precursorsoccurring in flight toward the substrate and/or on the substrate.

While whiteboards and coated walls have been described, the coatings canbe applied to other forms. For example, referring now to FIG. 3, any ofthe materials described herein can be applied to a continuous sheet ofmaterial, such as paper, to provide a product 50 that includes asubstrate 52 and a coating 54 extending upon the substrate 52. As shownin FIG. 3, the product 50 can be conveniently stored in a roll form. Ifdesired, product 50 can be cut, e.g., along a transverse line 60, toprovide individual sheets 70 of material. Referring now to FIG. 4,sheets 70 can be fashioned into a product 80 in tablet form usingfasteners 82. If desired, the assembled sheets can have perforations 86,allowing sheets to be torn from the tablet and used as a mobilewritable-erasable product.

Blends of polyurethane materials and any one of, some of, or all ofepoxy resins, acrylic resins described herein can be used to make thecoatings having the writable-erasable surface.

Other water-based materials may be used alone, or in combination withother water-based materials described herein, such as polyurethanematerials. For example, epoxy resins in a water-based carrier may beutilized. These epoxy resins may be used in conjunction with variouscrosslinkers and/or additives described herein. For example, thecrosslinkers can be a moiety that includes a plurality of amino groups,thiol groups, hydroxyl groups or mixtures of such groups. Water-basedepoxy resins are commercially available under the name Enducryl® fromEpoxy Systems, Inc.

The first and second components can be applied to the substrate, e.g.,by concurrently spraying the components so that they mix in flightand/or on the substrate, and then optionally applying a crosslinkingpromoter, such as an acid, to the mixed first and second components,e.g., in the form of a solution. In still other implementations, acrosslinking promoter is first applied to the substrate, and then thefirst and second components are applied to the substrate having thecrosslinking promoter.

The first and second components can be mixed, e.g., by alternatelyadding the desired, pre-determined quantities of the components from alarge drum to a paint bucket, mixing, and then applying the coating on asubstrate. The advantage of this method is that the pot life of thecomponents are preserved without wasting the components.

Still other implementations are within the scope of the followingclaims.

1. A composition comprising: an isocyanate resin component selected fromthe group consisting of hydrophilic aliphatic diisocyanate monomers,hydrophilic aliphatic diisocyante homopolymers, hydrophilic aliphaticdiisocyanate oligomers, and combinations thereof, and an acrylic polyolresin component, wherein at least one of the isocyanate resin componentand the acrylic polyol resin component is in a water-based carrier, andfurther wherein a) the isocyanate resin component comprises 20-40% byweight of the composition, b) the acrylic polyol resin componentcomprises 10-20% by weight of the composition, and c) the isocyanateresin component and the acrylic polyol resin component are present inrelative amounts with respect to each other such that when theisocyanate resin component and the acrylic polyol resin component arecombined with one another under ambient conditions, the compositioncures to form a material having a write-erasable surface, which materialhas at least one characteristic selected from the group consisting of: aSward hardness of greater than about 25; a Taber abrasion of less than150 mg/thousand cycles; the elongation at break between about 5 percentand about 400 percent; the sag resistance between about 4 mils to about24 mils; a contact angle measured from the surface of the material usingdeionized water of less than about 150 degree; and combination thereof;which material is further characterized in that, when its surface iswritten on with a marking material comprising a colorant and a solvent,the solvent comprising one or more of water, alcohols, alkoxy alcohols,ketones, ketonic alcohols, esters, acetates, mineral spirits, ormixtures thereof, the marking material can be erased from the surface ofthe write-erasable material to be substantially invisible for more than100 cycles of writing and erasing at the same position.
 2. Thecomposition of claim 1, wherein the isocyanate resin component and theacrylic polyol resin component are present in relative amounts withrespect to each other such that when the isocyanate resin component andthe acrylic polyol resin component are combined with one another underambient conditions, the composition cures to form a material having awrite-erasable surface, which material is characterized in that: itshows a Swath hardness of greater than about 25; a Taber abrasion ofless than 150 mg/thousand cycles; the elongation at break between about5 percent and about 400 percent; the sag resistance between about 4 milsto about 24 mils; and a contact angle measured from the surface of thematerial using deionized water of less than about 150 degree; and whenits surface is written on with a marking material comprising a colorantand a solvent, the solvent comprising one or more of water, alcohols,alkoxy alcohols, ketones, ketonic alcohols, esters, acetates, mineralspirits, or mixtures thereof, the marking material can be erased fromthe surface of the write-erasable material to be substantially invisiblefor more than 100 cycles of writing and erasing at the same position. 3.The composition of claim 1, further comprising titanium dioxide, asurface additive, a wetting agent, or a defoaming agent.
 4. Thecomposition of claim 1, further comprising a pigment or a colorant. 5.The composition of claim 1, wherein the composition has volatile organiccompounds (VOCs) in a range of about 0 g/L to about 350 g/L.
 6. Thecomposition of claim 1, wherein the composition has VOCs in a range ofabout 0 g/L to about 50 g/L.
 7. The composition of claim 1, wherein: theisocyanate resin component is in a first container and the acrylicpolyol resin component is in a second container.
 8. The composition ofclaim 7, wherein one or both of the isocyanate resin component and theacrylic polyol resin component are in the form of a dispersion.
 9. Thecomposition of claim 1, wherein the isocyanate resin component isselected from the group consisting of hydrophilic aliphatic diisocyanatehomopolymers, hydrophilic aliphatic diisocyanate oligomers, andcombinations thereof.
 10. The composition of claim 1, wherein thehydrophilic aliphatic diisocyanate is homopolymerhexamethylene-1,6-diisocyanate.
 11. The composition of claim 1, whereinthe material having a write-erasable surface has a porosity of less thanabout 40 percent.
 12. The composition of claim 1, wherein the materialhaving a write-erasable surface has a thickness of from about 0.001 inchto about 0.125 inch.
 13. The composition of claim 1, wherein thematerial having a write-erasable surface has a Taber abrasion value offrom about 100 mg/thousand cycles to about 125 mg/thousand cycles. 14.The composition of claim 1, wherein the material having a write-erasablesurface has VOCs in a range of about 0 g/L to about 350 g/L.
 15. Thecomposition of claim 1, wherein the material having a write-erasablesurface has VOCs in a range of about 0 g/L to 50 g/L.
 16. Thecomposition of claim 1, wherein the material having a write-erasablesurface has an average surface roughness (R_(a)) of less than about7,500 nm.
 17. The composition of claim 1, wherein the material having awrite-erasable surface has maximum surface roughness (R_(m)) of lessthan about 10,000 nm.
 18. The composition of claim 1, wherein thematerial having a write-erasable surface has a contact angle of greaterthan about 35 degrees on its surface.
 19. The composition of claim 1,wherein the material having a write-erasable surface is characterised inthat, its surface is written on with a marking material comprising acolorant and a solvent, the solvent comprising one or more of water,alcohols, alkoxy alcohols, ketones, ketonic alcohols, esters, acetates,mineral spirits, or mixtures thereof, the marking material can be erasedfrom the surface of the write-erasable material to be substantiallyinvisible after writing and erasing at the same position for more thanabout 5,000 cycles.